Financial markets have become stimulus junkies. They crave their next fix of quantitative easing and when they don’t get it they turn ugly. The rush they get from the drug wears off after a while, and then they become needy and whiny. Witness last week’s sell-off on Wall Street following the hint from the Federal Reserve that it was about to cut off the drug supply.

A similar dependency exists in the UK, where stock market traders expectantly await an injection of QE, courtesy of the Bank of England, after deterioration in the UK’s economic outlook. Governor Sir Mervyn King voted for another £25bn of cheap money and his colleagues should endorse his view in the coming months. The loss of the UK’s much coveted AAA status, thanks to the credit ratings agency Moody’s on Friday night, is likely to make the markets salivate even more.

The prospect of US policymakers taking the opposite view, and raising interest rates, prompted a bit of soul-searching. The markets have rallied strongly since the middle of 2012, but appeared acutely vulnerable to the suggestion that monetary conditions might at some point return to something like normal. For those who don’t have long enough memories to remember what normal is, that would be a world with official interest rates between 3% and 5% and where the electronic printing presses are mothballed.